In the automated assembly of head gimbal assemblies (HGA's) for hard disk drives, an industrial robot is used to pick up a magnetic read/write head from a feeder nest. The robot uses an end effector consisting of a hollow needle through which is drawn a vacuum. Due to the minute size of the head, tolerance build up in the feeder nest and robot positioning, it is not possible to pick up a head accurately enough to place it directly into an assembly fixture.
In the prior art, several methods of accurately locating the head in relation to the robot end effector have been used. In one method, the edges of the head are lightly bumped against a fixed edge while holding the head on the end of the needle with a vacuum. This method is time consuming and slows the assembly process. Another method uses a vision system to locate the head in relation to the robot end effector. Although this system is faster than the bumping method, vision systems are complex and relatively expensive. A fast, cost effective method for aligning a magnetic read/write head during automated assembly is needed.